The present invention is related to a digital camera, and more specifically, directed to a highspeed image selecting method and a digital camera equipped with a highspeed image selecting function, by which an enlarged thumbnail image is fed in fast-forward/fast-backward modes when an image is displayed on a display unit such as a liquid crystal display.
Very recently, digital cameras (electronic still image cameras) have been developed, and are commercially available, and thus are gradually popularized.
A digital camera is arranged as follows. Imaging (photographing) light is photoelectrically converted into image data, and this image data is recorded on a recording medium, and thereafter is outputted to an external image processing apparatus, for instance, a personal computer. Then, the image data is processed by way of a printing image data forming process in the external image processing apparatus, and then the formed printing image data is outputted to a printer, so that a photographed image is printed/reproduced on a print paper.
It should be noted that the most digital cameras are equipped with liquid crystal displays (LCD) for displaying photographed images and the like. On the other hand, image data acquired by photoelectric converting operation are compression-processed to be recorded on recording media. Normally, the compression process operation is carried out based on the JPEG (Joint Photographic Image Coding Experts Group) standard (will be referred to as xe2x80x9cJPEG compressionxe2x80x9d hereinafter).
In the case that an image is selected on the side of a personal computer, a plurality of thumbnail images are previously acquired to be displayed on a monitor, and a user selects a desirable image. Then, the selected image data is acquired from a digital camera to be expanded, and the expanded image is displayed on the monitor. After this expanded image is confirmed by the user, this image is processed by executing a color printing image data forming process, and then this processed image is printed out by a printer connected to the personal computer.
A thumbnail image corresponds to a compressed image which is used when a desirable image is selected from image data acquired by a personal computer and the like. Assuming now that a data size (namely memory capacity) of image data for 1 frame is equal to 1,024xc3x97768 pixels, a thumbnail image corresponding to this 1-frame image is such a compressed image having approximately 86xc3x9760 pixels by thinning image data from this 1-frame image data. Then the thumbnail image is recorded on a recording medium of a digital camera.
In such a system that a digital camera is connected to a communication line and a wireless (radio) unit such as a portable telephone so as to transmit desirable image data via either a wire line or a wireless line, and/or in order to directly transmit printing image data from the digital camera to a printer to be printed out, this system should be arranged in a manner that the images are reproduced on a liquid crystal display on the side of the digital camera so as to select a desirable image.
However, since the image data have been JPEG-compressed to be stored in the recording medium, these JPEG-compressed image data stored in this recording medium should be read out and then be expanded, and thereafter be extended over a frame memory in order to reproduce/display the images on the liquid crystal display.
When expanding means for compressed data is constituted by a hardware circuit, expanding/extending process time of these compressed data may be shortened. However, in popularized digital cameras, expanding means are normally arranged in a program form (will be referred to as an xe2x80x9cexpanding programxe2x80x9d hereinafter) so as to reduce product cost. In such popularized digital cameras, 2 to 3 seconds are necessarily required to expand a 1-frame image (1,024xc3x97768 pixels) which has been JPEG-compressed by using this expanding program.
As a result, there is a problem that users have such feelings that image display time would be prolonged. Moreover, when a desirable image is selected, image data must be sequentially read out to be displayed. Under such a circumstance, if a desirable image is stored in a later order, then a long time duration is actually required in order to select this desirable image. Thus, there is a further problem that such a lengthy access time is practically inconvenient.
The present invention has been made to solve the above-described problems, and therefore, has an object to provide a highspeed image selecting method, and also a digital camera equipped with a highspeed image selecting function, capable of enlarging a thumbnail image to feed the enlarged thumbnail image in a fast mode.
To achieve objects, a highspeed image selecting method, according to a first aspect of the present invention, is featured by such a highspeed image selecting method for selecting an image photographed by a digital camera, comprising the steps of: enlarging and feeding the enlarged thumbnail images sequentially in fast-forward/fast-backward modes to be sequentially displayed; and when a desirable thumbnail image is selected from the enlarged thumbnail images under display, extending compression image data corresponding to the selected thumbnail image so as to acquire image data.
In this first aspect, the thumbnail image is fed in the fast-forward/fast-backward modes to be displayed in a high speed. After a desirable thumbnail image is selected, the compressed image data is expanded, so that the image can be selected in a high speed.
In accordance with a second aspect of the present invention, in the highspeed image selecting method of the first aspect, the enlarged thumbnail images are indexed, and then the enlarged thumbnail images with the indexes are sequentially fed in the fast-forward/fast-backward modes to be sequentially displayed.
In this second aspect, the thumbnail images with the indexes are enlarged and the enlarged thumbnail images are fed in the fast-forward/fast-backward modes, so that the image can be further easily selected.
In accordance with a third aspect of the present invention, a digital camera equipped with a highspeed image selecting function is featured by that in a digital camera for recording on a recording medium, image data produced by photoelectrically converting photographing light and thumbnail image data thereof, a digital camera equipped with a highspeed image selecting function, comprising: a display unit for displaying an image; data expanding means for expanding compressed image data; thumbnail enlarged image display means for enlarging thumbnail image data and for displaying the enlarged thumbnail image data on the display unit; thumbnail image selecting means for feeding the enlarged thumbnail image under display in fast-forward/fast-backward modes to select a desirable thumbnail image; image display means for displaying image data corresponding to the selected thumbnail image on the display unit; and selection image defining means for defining the displayed image as a selection image.
In this third aspect, the thumbnail image is fed in the fast-forward/fast-backward modes to be displayed in a high speed. After a desirable thumbnail image is selected, the compressed image data is expanded, so that the image can be selected in a high speed.
In accordance with a fourth aspect of the present invention, a digital camera equipped with a highspeed image selecting function is featured by that the fast-forward/fast-backward feeding operations of the enlarged thumbnail image by the thumbnail image selecting means are commenced by executing a predetermined switch operation.
In accordance with the fourth aspect, the enlarging process and the fast-forward/fast-backward feeding operations of the thumbnail image can be readily realized by a predetermined switch operation, so that the thumbnail images can be selected in a high speed.
A digital camera equipped with a highspeed image selecting function according to a fifth aspect of the present invention, is featured by that in the digital camera equipped with the highspeed image selecting function, as described in the third aspect or the fourth aspect, the fast-forward/fast-backward feeding operations of the enlarged thumbnail image by the thumbnail image selecting means are commenced when an instruction is issued such that forward/backward feeding operations of normal image data are continuously performed within a predetermined time period.
In accordance with the fifth aspect, when the image selection is continuously performed within a predetermined time period, the operation is automatically transferred to the enlarging operation and the fast-forward/fast-backward operations of the thumbnail image, so that the thumbnail image can be readily selected in a high speed. Also, since the enlarged thumbnail image is displayed until the image data is displayed, the waiting tension given to the user can be relaxed.
A digital camera equipped with a highspeed image selecting function, according to a sixth aspect of the present invention, is featured by that in the digital camera equipped with the highspeed image selecting function, as described in the third aspect, the fourth aspect, or the fifth aspect, the expanding process of the image data by the data expanding means is carried out in conjunction with the display process of the enlarged thumbnail image corresponding thereto.
According to the sixth aspect, since the enlarging/display process operation of the thumbnail image and the expanding process of the image data are carried out, the image data can be quickly displayed after the selecting operation.
A digital camera equipped with a highspeed image selecting function, according to a seventh embodiment of the present invention, is featured by that the digital camera equipped with the highspeed image selecting function, as described in any one of the preceding aspects 3 to 6, is further comprised of: indexing means for indexing the enlarged thumbnail image displayed by the thumbnail enlarged image display means.
In accordance with the seventh embodiment, since the enlarged thumbnail images are indexed, the image selection by the fast-forward/fast-backward operation can be readily performed.
A recording medium, according to an eighth aspect of the present invention, is featured by such a recording medium readable by a digital camera for recording on the recording medium, image data produced by photoelectrically converting photographing light and also thumbnail image data thereof, on which a program is recorded and the program is capable of realizing: a data expanding function for expanding compressed image data; a thumbnail enlarged image display function for enlarging the thumbnail image data and for displaying the enlarged thumbnail image data on a display unit; a thumbnail image selecting function for feeding the enlarged thumbnail image under display in fast-forward/fast-backward modes to select a desirable thumbnail image; an image display function for displaying the expanded image data corresponding to the selected thumbnail image or the display unit; and a selection image defining function for defining the displayed image as a selection image.
Since the program recorded on the recording medium according to the eighth aspect of the present invention is executed, the enlarged thumbnail image can be fed in the fast-forward/fast-backward operations.